This invention is related to a technique for monitoring the exposure of selected publications to readers and, more particularly, to an accurate, reliable electronic technique for determining when an individual who has been selected as a test subject is positioned close enough to the publication so that he is likely to be reading it.
Various techniques are now in use to determine the readership of selected publications. Such publications are typically magazines. The term "magazine" will be used hereinafter to include any type of publication. Publishers and advertisers require this information in order to determine readership which, in turn, is useful to set printing runs, establish advertising rates, indicate geographic areas for concentrating resources, and provide an analysis of economic and social categories of the readership, and the like.
To currently obtain this information, such surveys are conducted primarily in one of two ways. Firstly, individuals are contacted personally or by phone and interviewed as to their magazine preferences. However, this method is inaccurate because it relies on memory recall of the individuals which has been shown as suspect and insufficiently accurate. Moreover, once the interviewer reveals the magazine in which he is interested, the selected individual being interviewed may develop a subjective inclination in favor of that magazine which may not in fact be true.
The second approach involves collecting a number of volunteer or paid individuals who are expected to keep a diary of their reading habits. The diaries are then retrieved periodically from the individuals, and analyzed. However, this approach relies exclusively on the accurate and complete record keeping of the particular individuals involved. Unfortunately, this also tends to be unreliable because people occasionally forget to make entries, they may be distracted from doing it, or, occasionally, may simply not be inclined to make an entry. Therefore, the techniques conventionally used up to the present time suffer from serious disadvantages which have caused concern about the accuracy, and therefore the underlying value, of such surveys.